Synthesis of spherical LiMn2O4 microparticles by a combination of spray pyrolysis and drying method

Lithium manganese oxide (LiMn2O4) has been synthesized by a spray pyrolysis method from the precursor solution; LiNO3 and Mn(NO3)2·6H2O were stoichiometrically dissolved into distilled water. The synthesized LiMn2O4 particles exhibited a pure cubic spinel structure in the X-ray diffraction (XRD) patterns, however they were spherical hollow spheres for various concentrations of precursor solution. Thus, the as-prepared LiMn2O4 particles were then ground in a mortar and dispersed into distilled water. To make a well dispersed slurry solution, a dispersion agent was also added into the slurry solution. The LiMn2O4 microparticles with a spherical nanostructure were finally prepared by a spray drying method from the slurry solution. The tap density of the LiMn2O4 microparticle prepared by a combination of spray pyrolysis and drying method was larger than that by a conventional spray pyrolysis method. -prepared samples were sintered at 750 °C for 1 h in air and used as cathode active materials for lithium batteries. Test experiments in the electrochemical cell Li|1 M LiClO4 in EC:DEC = 1:1|LiMn2O4 demonstrate that the sample prepared by the present method is a promising cathode active material for 4 V lithium-ion batteries at high-charge–discharge and elevated temperature operation. The LiMn2O4 compounds by the combination of spray pyrolysis and drying method are superior to that by the conventional spray pyrolysis method in terms of electrochemical characteristics and tap density.